docs: def reindex(self, mode, includes=""):
          """
          This operation allows you to generate or update the indexes for
          content; such as users, groups, and items stored in the database
          (store). During the process of upgrading an earlier version of
          Portal for ArcGIS, you are required to update the indexes by
          running this operation. You can check the status of your indexes
          using the status resource.
  
          Input:
             mode - The mode in which the indexer should run.
                    Values: USER_MODE | GROUP_MODE | RELATION_MODE |
                            SEARCH_MODEL | FULL
             includes  An optional comma separated list of elements to
                       include in the index. This is useful if you want to
                       only index certain items or user accounts.
          """
          url = self._url + "/indexer/reindex"
          params = {
              "f" : "json",
              "mode" : mode,
              "includes" : includes
          }
          return self._get(url=url,
                              param_dict=params,
                              securityHandler=self._securityHandler,
                              proxy_port=self._proxy_port,
                              proxy_url=self._proxy_url)